We are studying the way in which electron transfer occurs and is coupled to other chemical events, during the functioning of redox enzymes. We use steady state and pre-steady state kinetics methods, and EPR, NMR Mossbauer and absorbance spectroscopy to study such systems. We are currently studying hydrogenase and nitrogenase from C. pasteurianum and A. vinelandii, nitrate reductase from N. crassa, glutamate synthase from E. coli, and the adrenal steroid hydroxylases from mammals. We hope to understand the molecular mechanism and physiological control of these catalysts.